Re: That gives me these errors the sorenson?

What preset are you using? Custom or default? What kind of modifications are you making? Certain presets, (especially mpeg 2) allow for very little variation, so there's a lot of things that can cause squeeze to throw an error if you are modifying presets.
As far as the codecs go, this is something that is installed with the application. They are only available through the installer. However, squeeze will recognize and make available other compatible codecs if they are installed via other means such as Non Linear Editors, etc.